CN114424990A

CN114424990A - Medical support

Info

Publication number: CN114424990A
Application number: CN202210066962.1A
Authority: CN
Inventors: 张宇; 曹洋; 朱清; 张琳琳
Original assignee: Shanghai Tuomai Medical Technology Co ltd
Current assignee: Shanghai Tuomai Medical Technology Co ltd
Priority date: 2021-05-12
Filing date: 2021-05-12
Publication date: 2022-05-03
Also published as: CN112972082A; US20240108484A1; EP4338711A1; WO2022237504A1

Abstract

The invention provides a medical stent, which comprises a film covering section and a naked section; the film laminating section comprises a cutting support body and a film material arranged on the cutting support body; at least one end of the film covering section is connected with the naked section, and at least one naked section comprises a braided stent body; wherein the cover segment comprises a first segment configured such that an inner diameter of the first segment in a first expanded state is less than an inner diameter of the cutting stent body in a free state, and the first segment expands radially outward when subjected to a radially outward external force. This medical support has good compliance and support nature, and the propelling movement of being convenient for satisfies the user demand, and can adjust the internal diameter of first section according to actual need, has better universal suitability.

Description

Medical support

The medical stent is applied by division, the original application number is 202110514247.5, the application date is 2021, 05 and 12, and the name is medical stent.

Technical Field

The invention relates to the technical field of medical instruments, in particular to a medical bracket.

Background

The portal vein pressure is continuously increased due to liver cirrhosis, portal vein main obstruction, hepatic vein obstruction or other unknown reasons, which are commonly called portal hypertension. The blood flow of portal hypertension is characterized in that portal blood can not smoothly flow back into inferior vena cava through liver, meanwhile, portal-body vein traffic branches are opened, a large amount of portal blood directly enters body circulation through the traffic branches without passing through the liver, and clinical symptoms are represented by abdominal wall and esophageal vein expansion, splenomegaly, splenic hyperfunction, liver function decompensation and ascites, portal hypertension gastrointestinal vascular wall and the like, and esophageal and gastric variceal bleeding can also occur in severe cases.

Transjugular Intrahepatic Portosystemic Shunt (TIPS) is a portal hypertension treatment method developed on the basis of increasing maturity of Transjugular angiography and percutaneous Transjugular hepatic puncture technologies, and can keep unobstructed for a long time by opening a hepatic vein and a portal vein channel and implanting a bracket in the channel for supporting. When the stent in the prior art is applied to TIPS, the defects of poor flexibility, difficult pushing or poor supporting performance exist. In addition, the diameter of current medical support is fixed size generally, is 8mm, 10mm, 12mm respectively, and the operator selects the support that the diameter matches according to actual need when carrying out the operation, and when not having suitable support just, the operator can select the support of great diameter, and this although can reduce portal hypertension, also can increase the risk that the later stage takes place hepatic encephalopathy.

Disclosure of Invention

The invention aims to provide a medical stent which has good flexibility and support property and meets the use requirement of TIPS.

In order to achieve the above object, the present invention provides a medical stent, comprising a covered section and a bare section; the film laminating section comprises a cutting support body and a film material arranged on the cutting support body; at least one end of the film covering section is connected with the naked section, and at least one naked section comprises a braided stent body; wherein the film-covered section comprises a first section;

the medical stent further comprises a second binder sleeved outside the first section, and the medical stent is configured such that when the medical stent is in a first expanded state, the inner diameter of the second binder is smaller than the outer diameter of the coating section in a free state, and the second binder applies a radial binding force to the cutting stent body, and when the first section is subjected to an external force radially outward, the second binder is plastically deformed or broken, and the radial binding force is reduced, so that the first section is expanded radially outward.

Optionally, the braided stent body is braided from wire material; the medical stent also comprises a first binding piece, wherein the first binding piece is arranged on the braided stent body and binds the end head of the wire.

Optionally, the woven stent body is in hot-melt connection with the membrane material; and/or the medical stent also comprises a connecting band, and the connecting band penetrates through the pores on the woven stent body and is in hot-melt connection with the membrane material.

Optionally, in the axial direction of the medical stent, the number of the pores on the braided stent body is 3-9; and/or the number of the pores on the woven stent body is 4-8 in the circumferential direction of the medical stent.

Optionally, the second binding piece is formed by connecting linear structures end to end; and/or a weakening structure is arranged on the second binding piece to reduce the strength of the second binding piece.

Optionally, the weakening structure comprises at least one of a hole or a groove.

Compared with the prior art, the medical bracket has the following advantages: firstly, the medical stent comprises a film covering section and a naked section; the film laminating section comprises a cutting support body and a film material arranged on the cutting support body; at least one end of the film covering section is connected with the naked section, and at least one naked section comprises a braided stent body; wherein the film-covered section comprises a first section; the medical stent is configured such that an inner diameter of the first section in a first expanded state is smaller than an inner diameter of the cutting stent body in a free state, and the first section expands radially outward when the first section is subjected to a radially outward external force. The medical stent has good supporting performance and flexibility, is particularly suitable for TIPS, can apply the external force to the membrane covering section according to actual needs to change the inner diameter of the first section so as to expand the applicability of the medical stent in the actual use process of the medical stent, and can effectively reduce the occurrence probability of hepatic encephalopathy by changing the inner diameter of the first section so as to obtain the medical stent with proper size for the TIPS.

Further, the naked section is direct with membrane material hot melt is connected or the naked section through the connecting band with membrane material hot melt is connected for naked section and tectorial membrane section firm in connection improve medical stent's performance.

Drawings

The drawings are included to provide a better understanding of the invention and are not to be construed as unduly limiting the invention.

Fig. 1 is a schematic structural view of a medical stent according to an embodiment of the present invention, in which a woven stent body is directly connected with a film material by heat fusion.

Fig. 2 is a schematic structural view of a medical stent provided by an embodiment of the invention, wherein a woven stent body is connected with a membrane material through a connecting band in a hot melting mode.

FIG. 3 is a schematic structural diagram of a medical stent according to an embodiment of the present invention, wherein a membrane material exerts a radial constraining force on a cutting stent body.

Fig. 4 is a schematic structural view of a medical stent according to an embodiment of the present invention, in which a second constraining member exerts a radial constraining force on a cutting stent body.

Fig. 5 is a schematic view of a second tether in the medical stent of fig. 4.

Fig. 6 is a schematic view of the second tether shown in fig. 4, with a weakened structure formed therein.

The reference numerals are explained below: 110-coated section, 110 a-first section, 110 b-proximal section, 110 c-distal section, 111-cut stent body, 112-membrane material, 121-woven stent body, 130-first binder, 140-connecting band, 150-second binder, 151-weakening structure, 160-visualization element.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.

Furthermore, each of the embodiments described below has one or more technical features, and thus, the use of the technical features of any one embodiment does not necessarily mean that all of the technical features of any one embodiment are implemented at the same time or that only some or all of the technical features of different embodiments are implemented separately. In other words, those skilled in the art can selectively implement some or all of the features of any embodiment or combinations of some or all of the features of multiple embodiments according to the disclosure of the present invention and according to design specifications or implementation requirements, thereby increasing the flexibility in implementing the invention.

As used in this specification, the singular forms "a", "an" and "the" include plural referents, and the plural forms "a plurality" includes more than two referents unless the content clearly dictates otherwise. As used in this specification, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise, and the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either fixedly connected, detachably connected, or integrally connected. Either mechanically or electrically. Either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

To further clarify the objects, advantages and features of the present invention, a more particular description of the invention will be rendered by reference to the appended drawings. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention. The same or similar reference numbers in the drawings identify the same or similar elements.

Fig. 1 to 4 are schematic structural views of a medical stent provided in an embodiment of the present invention. Referring to fig. 1 to 4, the medical stent includes a covering section 110 and a bare section. The film-coated section 110 comprises a cutting stent body 111 and a film material 112, wherein the film material 112 is coated on the cutting stent body 111. The cover segment 110 includes a first segment 110a, the medical stent is configured such that an inner diameter of the first segment 110a in a first expanded state is smaller than an inner diameter of the cutting stent body 111 in a free state, and the first segment 110a expands radially outward when the first segment 110a receives a radially outward external force. At least one end of the film covering section 110 is connected with the bare section, and the bare section comprises a braided stent body 121. It is understood that the cut stent body 111 is obtained by cutting a tube and then heat-setting, and the braided stent body 121 is obtained by braiding wires and then heat-setting. The medical stent is used for implantation in a patient at a predetermined position, for example, in Transjugular Intrahepatic Portosystemic Shunt (TIPS), for implantation in the liver and for establishing a blood flow channel between the hepatic vein and the portal vein, where the bare segment is used to allow a part of the blood flow to the liver tissue, avoiding atrophy of the liver tissue.

The medical stent provided by the embodiment of the invention combines the cutting stent body 111 and the weaving stent body 121 into a whole, has good supporting performance, can construct a stable blood flow passage in a liver, and has good flexibility, so that the medical stent can be smoothly pushed to a preset position. It should be noted that, when the medical stent includes only one bare segment, the bare segment is located at the distal end of the covered segment 110, so that the bare segment is located at the portal vein after the medical stent is implanted in the liver. As used herein, "distal" refers to the relative orientation, position, and direction of elements or actions with respect to one another from the perspective of a physician using the medical stent, and although not limiting, "distal" generally refers to the end that enters the patient first, as opposed to "proximal" which refers to the end that is closer to the physician.

The medical stent is preferably a self-expanding stent. In some embodiments, the cutting stent body 111 is made of 316L stainless steel for medical use, or nitinol or other shape memory alloy. The length of the cutting support body 111 may be 40mm to 100mm, preferably 40mm to 80mm, and more preferably 70mm to 80 mm. The width of the bracket rod formed by cutting is 0.09 mm-0.25 mm, and preferably 0.12 mm-0.18 mm. The thickness of the cutting support body 111 is 0.18 mm-0.25 mm. The support rods can be in a sine wave shape or a triangular wave shape, and each support rod can comprise 4-8 wave crests, preferably 4-6 wave crests in the circumferential direction of the medical support. The film material 112 covers at least the outer surface of the cutting support body 111, and preferably, the film material 112 covers both the inner surface and the outer surface of the cutting support body 111. The thickness of the membrane material 112 is 20um to 120um, preferably 25um to 60 um. The membrane material 112 should have good permeability, and the material of choice is PET or ePTFE, preferably ePTFE. The diameter of the wire used for weaving the braided stent body 121 is 0.15mm to 0.25mm, preferably 0.20mm to 0.25mm, and the material thereof can be shape memory alloy, specifically at least one of Au-Cd, Ag-Cd, Cu-Zn-Al, Cu-Zn-Sn, Cu-Zn-Si, Cu-Sn, Cu-Zn-Ga, Au-Cu-Zn, NiAl, Fe-Pt, Ti-Ni-Pd, Ti-Nb, U-Nb and Fe-Mn-Si. The length of the braided stent body 121 may be 15mm to 45mm, preferably 20mm to 40 mm. The shape of the pores in the woven stent body 121 is rhombic, the number of the rhombic holes is 3-9, preferably 3-8, more preferably 4-8 in the axial direction of the medical stent, and the number of the rhombic holes is 4-8, preferably 4-6 in the circumferential direction of the medical stent.

Preferably, the medical stent further comprises a first binder 130, the first binder 130 is disposed on the braided stent body 121 and binds the ends of the wires to maintain the structure of the braided stent body 121 from being unraveled. In some embodiments, the first binding member 130 is a tube having an inner diameter slightly larger than an outer diameter of the wire, such that a tip of the wire can extend into the interior of the tube and be bound by the tube. According to the diameter of the wire, the inner diameter of the pipe can be 0.0075inch to 0.0100inch, preferably 0.0075inch to 0.0095 inch. In addition, the number of the first tethers 130 is equal to the number of wires used to weave the braided stent body 121, for example, when the braided stent body 121 is woven from one wire, the number of the first tethers 130 is one, and when the number of the wires is two, the number of the first tethers 130 is two, and each of the first tethers 130 tethers two ends.

Alternatively, as shown in fig. 1, the woven stent body 121 is directly heat-fused to the membrane material 112 of the membrane covering section 110. And/or, referring to fig. 2, the medical stent further includes a connecting band 140, and the connecting band 140 passes through the pores of the braided stent body 121 and is connected with the membrane material 112 in a hot-melt manner. The material of the connecting band 140 is preferably the same as that of the film material 112, which is beneficial to melting the film material 112 and the connecting band 140 into a whole, and further improves the connecting strength of the film-coated section 110 and the bare section. Generally, the connecting band 140 passes through the pores of the braided stent body 121 closest to the membrane covering section 110 and then connects with the membrane material 112.

In addition, more than two developing elements 160 may be disposed on the coating section 110, more than two developing elements 160 may be disposed on opposite ends of the coating section 110, and at least one of the developing elements 160 is a developing ring. When the medical stent includes only one of the bare segments, the developer ring is closer to the bare segment. The developing element can be made of developing metals such as platinum-iridium alloy, platinum-tungsten alloy, stainless steel, gold, tantalum and the like.

Further, referring to fig. 3 and 4 with emphasis, the covering membrane section 110 includes the first segment 110a, and the first segment 110a may extend from the proximal end to the distal end of the covering membrane section 110 (i.e., the whole covering membrane section 110 is completely composed of the first segment 110 a). Alternatively, the first segment 110a may occupy a localized area of the coating segment 110, such as the first segment 110a being located in a middle region of the coating segment 110, such that the coating segment 110 includes a proximal segment 110b, the first segment 110a, and a distal segment 110c (shown in FIG. 3) that are axially connected in series.

The first segment 110a has a first inner diameter d when the medical stent is in a first expanded state₁And when the cutting support body 111 is in a free state, the cutting support body 111 has a second inner diameter D, the first inner diameter D₁Smaller than the second inner diameter D. For the medical stent in the first expanded state, the first segment 110a is radially outwardly expandable when the first segment 110a is subjected to a radially outwardly directed external force. In other words, the first segment 110a has a variable inner diameter. In practice, when the medical stent is released after being delivered to a predetermined position in a body, the medical stent can be expanded to the first expanded state under the action of self-expansion tension, and then if the inner diameter of the first segment 110a needs to be increased continuously, external force can be applied to the first segment 110a through the balloon, so that the first segment 110a is expanded continuously and the inner diameter is increased continuously.

Thus, the medical stent is particularly suitable for TIPS, particularly when the patient actually requires an inner diameter d₂When the medical stent is used, the operator can select the medical stent provided by the embodiment, and the size of the medical stent meets the requirement d₁≤d₂Less than or equal to D. When the medical stent is usedHas a size of d₁＜d₂When D is less than D, the operator may release the medical stent and expand the medical stent to the first expanded state, and then apply an external force to the first segment 110a by using a balloon to expand the first segment 110a until the diameter of the first segment 110a reaches D₂And (4) finishing. Therefore, the medical stent has good universality, and when the medical stent is applied to TIPS, the medical stent can not only reduce portal hypertension, but also greatly reduce the occurrence probability of hepatic encephalopathy. Not only this, the first segment 110a can be re-expanded by the balloon to achieve greater shunt once in-stent restenosis occurs at a later stage, as long as the first segment 110a is not expanded to the second inner diameter D at the time of release.

In the case of a self-expanding stent, the "free state" refers to a state in which the cut stent body 111 is not subjected to a radial constraining force from the outside. As such, the medical stent may be in the first expanded state in the embodiment of the present invention by subjecting the region of the cutting stent body 111 corresponding to the first section 110a to a radial restraining force greater than the self-expanding tension of the cutting stent body 111. The self-expanding tension is the radially outward spring force generated by the cutting stent body 111 when subjected to a radial restraining force.

Specifically, in an alternative implementation, please refer to fig. 3 with emphasis, the medical stent is configured such that when the medical stent is in the first expanded state, an inner diameter of a region of the film 112 covering the outer surface of the cutting stent body 111 corresponding to the first segment 110a is smaller than an outer diameter of the cutting stent body 111 in the free state, so that the region of the film 112 corresponding to the first segment 110a applies the radial binding force to the cutting stent body 111 and prevents the cutting stent body 111 from expanding further, thereby enabling the first segment 110a to have the first inner diameter d₁. When the first segment 110a is subjected to the external force, the area of the membrane material 112 corresponding to the first segment 110a is plastically deformed and the radial constraint force is reduced to be less than the self-expansion force of the cutting stent body 111, so that the external force is applied to the first segment 110aThe cutting stent body 111 may continue to expand. The term "plastic deformation" refers to a deformation that is not self-recoverable. That is, when the external force is removed, the current inner diameter of the first segment 110a is greater than the first inner diameter d compared to the first expanded state₁。

Referring again to fig. 4, in an alternative implementation, the medical stent includes a second tie 150 having a ring shape, the second tie 150 being fitted over an outer surface of the first segment 110 a. The second tie 150 is configured such that when the medical stent is in the first expanded state, the inner diameter of the second tie 150 is smaller than the outer diameter of the cutting stent body 111 in the free state, such that the second tie 150 applies the radial tie force to the first segment 110a and prevents further expansion of the cutting stent body 111. When the first segment 110a is subjected to the external force, the second tie-down 150 is plastically deformed and reduces the radial tie-down force to less than the self-expanding tension of the cutting stent body 111, so that the cutting stent body 111 may continue to expand to cause the first segment 110a to continue to expand. It is understood that the second binder 150 may be broken when the external force is increased to a predetermined value. The predetermined value is determined according to the strength of the second tie down 150 itself.

Referring to fig. 5, optionally, the number of the second constraining pieces 150 is at least one, each of the second constraining pieces may be formed by connecting end to end a linear structure, and when the external force reaches the predetermined value, the second constraining pieces 150 are broken at the end to end connection. The predetermined value is determined according to the connection strength of the connection. Alternatively, referring to fig. 6, a weakening structure 151 is disposed on the second constraint element 150, and the weakening structure 151 is disposed to reduce the strength of the second constraint element 150, so that the second constraint element is easily plastically deformed or broken when subjected to the external force. It will be appreciated that in this case, the second tie-down 150 has a width to allow the weakening structure 151 to be provided. In the present embodiment, the weakening structure is merely a name description, and does not indicate a specific property. Alternatively, the weakening structure is, for example, a hole,the number and shape of the holes are not particularly limited in the embodiments of the present invention. Generally, the number of the holes may be 4 to 50, preferably 8 to 20, and the area of each hole may be 1mm²～4mm²Preferably 3mm²～4mm²。

It should be noted that, when the medical stent is applied to TIPS, the medical stent is implanted in the liver, liver tissue is attached to the outer surface of the medical stent, and when the second binder 150 is broken, the second binder 150 does not separate from the coating segment 110 under the compression of the liver tissue.

The use of the medical stent including the first segment 110a is described next, and the medical stent is applied to TIPS. The inner diameter d of the medical stent actually required in the process₂And a first inner diameter d of the first segment 110a₁And a second inner diameter D of the cutting support body 111 satisfies D₁＜d₂< D is illustrated as an example.

First, the practitioner performs shunt preparation and pre-operative assessment.

Next, the operator calculates the value of PPG (portal vein pressure gradient) from the pre-operative assessment and selects a medical stent with an appropriate inner diameter.

Next, the medical stent is implanted within the liver and self-expanded to the first expanded state.

Then introducing a balloon, and applying an external force to the first section 110a of the medical stent by using the balloon so as to continuously expand the first section 110a until the inner diameter of the first section 110a reaches d₂And (4) finishing.

At a later stage, if the medical stent is restenosis, the operator may reintroduce the balloon and expand the first segment 110a again to obtain greater flow diversion.

Although the present invention is disclosed above, it is not limited thereto. Various modifications and alterations of this invention may be made by those skilled in the art without departing from the spirit and scope of this invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A medical stent is characterized by comprising a film covering section and a naked section; the film laminating section comprises a cutting support body and a film material arranged on the cutting support body; at least one end of the film covering section is connected with the naked section, and at least one naked section comprises a braided stent body; wherein the film-covered section comprises a first section;

2. The medical stent of claim 1, wherein the braided stent body is braided from wire material; the medical stent also comprises a first binding piece, wherein the first binding piece is arranged on the braided stent body and binds the end head of the wire.

3. The medical stent of claim 1, wherein the woven stent body is in a heat-fused connection with the membrane material; and/or the medical stent also comprises a connecting band, and the connecting band penetrates through the pores on the woven stent body and is in hot-melt connection with the membrane material.

4. The medical stent of any one of claims 1 to 3, wherein the number of pores on the braided stent body in the axial direction of the medical stent is 3 to 9; and/or the number of the pores on the woven stent body is 4-8 in the circumferential direction of the medical stent.

5. The medical stent of claim 1, wherein the second tie is formed by joining linear structures end to end; and/or a weakening structure is arranged on the second binding piece to reduce the strength of the second binding piece.

6. The medical stent of claim 5, wherein the weakening structure comprises at least one of a hole or a groove.